(1) Field of the Invention
The present invention relates to an aircraft provided with hoist means, in particular a rotary wing aircraft, and also to the associated method.
Conventionally, hoist means comprise a winch arranged above a cabin of a rotary wing aircraft, for example, such a winch having a rotary drum for winding in and out a cable that serves in particular to lift or transport an external load.
The winch is arranged on a flank of the aircraft, e.g. above a cabin.
That type of installation is nevertheless limiting on light aircraft. When the winch carries a heavy load, e.g. of the order of 150 kilograms (kg), the aircraft tends to tilt with a roll movement towards the side of said load. In addition, there is a particularly large impact on centering the aircraft.
Under such circumstances, a light helicopter provided with a winch on a side flank is capable of carrying only a relatively small load, e.g. less than 150 kg, whereas a heavy helicopter may carry a load of more than 250 kg, for example.
(2) Description of Related Art
The technological background includes the following documents: DE 33 23 513, U.S. Pat. No. 4,750,691, U.S. Pat. No. 5,020,742, DE 197 09 380, U.S. Pat. No. 3,088,608, GB 2 303 837, WO 2005/025984, and U.S. Pat. No. 4,013,270.
Document DE 33 23 513 describes an aircraft provided with a winch carried by one end of a support, the support comprising an extendible beam fastened inside a cabin. The winch is situated vertically above the load that is to be carried, and thus on the same side as the load relative to an anteroposterior plane of symmetry of the aircraft.
Document U.S. Pat. No. 4,750,691 describes hoist means including a retractable beam that is hinged on a flank of an aircraft. In addition, that hoist means is provided with a winch arranged on a faired zone of said flank, vertically in register with the fastening of the beam to the flank.
A cable from said winch then extends along said beam and leaves the aircraft via an outlet end for connection to attachment means.
When the beam is deployed out from the cabin, the cable enables external loads to be supported. The winch is then situated substantially vertically above the load to be carried, and on the same side of the anteroposterior plane of symmetry of the aircraft as said load.
Document U.S. Pat. No. 5,020,742 describes hoist means comprising a winch disposed on a flank of a helicopter and a beam for guiding the cable from said winch and serving to offset a hook of the cable away from the downwash of the lift rotor of the aircraft.
The winch and the load for carrying are both situated on the same side of the anteroposterior plane of symmetry of the aircraft.
Document DE 197 09 380 does not form part of the technical field of the invention since it relates to a building.
Document U.S. Pat. No. 3,088,608 provides for a pivoting beam, which beam is controlled by a motor situated vertically above the load carried by said beam, and thus on the same side of the anteroposterior plane of symmetry of the aircraft as said load.
Document GB 2 303 837 suggests using a winch co-operating with a deflector arm to space the winch cable away from the aircraft. The winch and the load carried by the winch are then both on the same side of the aircraft relative to an anteroposterior plane of symmetry of the aircraft.
Document WO 2005/025984 describes a lifesaving device rather than a hoist device, the lifesaving device having the function of snatching an individual while in flight.
That lifesaving device is fastened to the landing gear of an aircraft.
Document U.S. Pat. No. 4,013,270 describes a beam supporting a winch and a pulley.